The phenomenal growth in the demand for wireless communications has put persistent pressure on wireless network operators to improve the capacity of their communication networks. To improve the spectral efficiency of these networks, scarce radio resources have to be reused aggressively in neighboring cells. As a result, inter-cell interference has become a main source of signal disturbance, limiting not only the service quality to mobile terminals at the cell edges, but also the overall system throughput.
A coordinated multipoint (CoMP) system can mitigate inter-cell interference. In a CoMP system, a plurality of geographically contiguous cells—referred to as sub-cells—are grouped together to form a so-called CoMP cell. Each CoMP cell has a central controller that coordinates concurrent transmissions across its constituent sub-cells so as to minimize inter-cell interference within the CoMP cell (referred to herein as inter-sub-cell interference).
Known approaches to coordinating concurrent transmissions across the sub-cells of a CoMP cell send each transmission at maximum power. With each transmission sent at maximum power, these approaches select the set of mobile terminals served by the transmissions so that the mobile terminals in the set each achieve some minimum quality of service requirement (e.g., a minimum signal-to-interference-plus-noise ratio, SINR). While these approaches facilitate a high aggregate throughput of the transmissions, they nonetheless potentially waste a significant amount of power by always transmitting at maximum power.